The present invention relates to detection of electrically conductive fluids, and in particular to detecting and signaling the release of bodily fluids from human beings or animals.
For many years the objective of electrically detecting and indicating the presence of body fluids or other electrically conductive liquids has been pursued. Detecting such fluids often has involved using a pair of electrodes connected with a voltage source and a detector circuit intended to turn on an audible alarm when a gap between the electrodes is bridged by an electrically conductive fluid.
Devices for detecting body fluids are desired particularly for assisting in the prevention of diaper rash, for potty training of infants, and in curing enuretic youngsters, as well as for detecting the leakage of blood or other fluids after surgery and invasive diagnostic procedures. Such devices are also desired to monitor and record urinary incontinence and to facilitate better care for pressure sores in chronically bedridden persons.
Such devices could also be useful for detecting leaks in domestic hot water heaters or other liquid storage devices.
Previously available devices for use to detect human body fluids have many disadvantages. For example, some prior art devices are too bulky and uncomfortable for use in the groin area for monitoring urinary incontinence. Some prior art devices use cumbersome and unsafe long electric wires to interconnect the necessary component parts.
Other drawbacks of previously available devices include sensors which are too large or too small, are not shaped properly, or are made of materials which are not compatible with the human body or other intended environment. In particular, prior art devices have not satisfactorily provided for early detection of small amounts of body fluids. Also, many prior art devices are too expensive to manufacture economically or are impractical to use.
What is desired, then, is a system including an improved sensor and an associated alarm system for reliably and consistently detecting and signaling the presence of electrically conductive fluids under all conditions of use, without false alarms. Such a sensor should be of small size, comfortable to use, easy to maintain, clean, and prepare for reuse, self-powered, and portable. Preferably, a system incorporating such a sensor should have the ability to provide signals to remote monitors for collection and analysis of data, and should be simple to use.
The present invention provides improved apparatus and a method for its use to overcome the aforementioned shortcomings of the prior art and, in particular, provides an improved, simple, and versatile device for signaling the presence of electrically conductive fluids, such as urine, wound exudate, feces, blood, and water, and also provides a disposable absorbent pad for use in detecting such electrically conductive fluids.
An important feature of one embodiment of the present invention is the use of comfortable, soft, non-absorbent material to support an absorbent sensor and a housing for a signaling device including an electrical circuit which form parts of the device.
In one embodiment of the invention a fluid-absorbent sensing pad has two apart-spaced electrodes, included in the structure of the absorbent pad and available to be connected electrically to the signaling device.
One embodiment of the invention provides a sensing pad whose design and shape provide comfortable positioning and detection of even very small amounts of body fluids for either male or female users.
It is a feature of one embodiment of the present invention that the fluid-detecting electrode system is compatible with different signaling devices that provide vibratory, audible, visible, or wireless signals.
One embodiment of the invention provides a disposable fluid-absorbent sensor material which can be cut to a desired length from a continuous roll.
One embodiment of the invention includes a radio transmitter and an encoding device for sending a signal which is identifiably encoded for reception and interpretation by a remotely located receiver, which may be portable.
In one embodiment of the invention encoded information may include identification of the source of the encoded signal, while equipment associated with the receiver can record the received signal identification information as well as time of receiving a signal, and can then compute elapsed time since an earlier signal was received, and other information.
One embodiment of the invention includes the use of an FM radio transmitter which transmits on the commercial FM broadcast frequency band. Signals from such an FM transmitter can be received by conventional domestic radio receivers, enabling most users to have more than one remote receiver.
The foregoing and other objectives, features, and advantages of the invention will be more readily understood upon consideration of the following detailed description of the invention, taken in conjunction with the accompanying drawings.